Hydraulic accumulators comprising a bellows that serves as an movable separating element are known and used in a plurality of technical fields, for example, in hydraulic brake systems for vehicles and in various kinds of industrial hydraulic systems. EP 1 052 412 A2, for example, discloses a bellows accumulator with a metal bellows that serves as a movable separating element between a gas side and a fluid side.
In hydraulic accumulators of this type, the bellows represents the element with the highest stress and the component that is critical to operational safety. While the risk of damage is rather low when the bellows is extended so that the folds of the bellows that have approached one another are moved away from each other, compressive strain may occur when the bellows are completely contracted so that the adjacent folds of the bellows are compressed. Such a risk exists especially if total contraction of the bellows occurs suddenly in operation.